// adding a photon{} block to global_settings activates photon mapping.
// photons also need to be adjusted for light sources and objects.
global_settings {
  photons {
    spacing 0.01                 // specify the density of photons
    //count 100000               // alternatively use a total number of photons

    //gather min, max            // amount of photons gathered during render [20, 100]
    //media max_steps [,factor]  // media photons
    //jitter 1.0                 // jitter phor photon rays
    //max_trace_level 5          // optional separate max_trace_level
    //adc_bailout 1/255          // see global adc_bailout
    //save_file "filename"       // save photons to file
    //load_file "filename"       // load photons from file
    //autostop 0                 // photon autostop option
    //radius 10                  // manually specified search radius
    // (---Adaptive Search Radius---)
    //steps 1
    //expand_thresholds 0.2, 40
  }
}